Spectrally-encoded endoscopy techniques, apparatus and methods

ABSTRACT

Exemplary apparatus for method for forming at least one spectral encoding endoscopy configuration. For example, it is possible to modify a spacer configuration and an lens optics configuration to have respective predetermined lengths, and also to modify a dispersive optics configuration to have a further predetermined length. Further, the modified spacer and modified lens optics configurations can be attached to one another to form a combined spacer-lens optics configuration. The modified dispersive optics configuration can be attached to a substrate to form to form a grating substrate configuration. Additionally, the combined spacer-lens optics configuration can be connected to an optical fiber, and the modified attached dispersed optics configuration can be connected to the modified attached lens optics configuration to form the spectral encoding endoscopy configuration(s) which can extends along a particular axis. The dispersive optics configuration can be modified to be at a predetermined angle with respect to the particular axis.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application is a continuation of U.S. patent applicationSer. No. 15/376,144 filed on Dec. 12, 2016 which is a continuation ofU.S. patent application Ser. No. 14/465,960 filed Aug. 22, 2014, whichissued as U.S. Pat. No. 9,516,997 on Dec. 13, 2016, which is acontinuation of U.S. patent application Ser. No. 13/427,463 filed Mar.22, 2012 which issued as U.S. Pat. No. 8,818,149 on Aug. 26, 2014, whichis a divisional of U.S. patent application Ser. No. 11/623,852 filedJan. 17, 2007, which issued as U.S. Pat. No. 8,145,018 on Mar. 27, 2012.This application is also based upon and claims the benefit of priorityfrom U.S. Patent Application Ser. No. 60/760,139, filed Jan. 19, 2006.The entire disclosures of such applications are incorporated herein byreference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

The invention was made with the U.S. Government support under ContractNo. BES-0086709 awarded by the National Science Foundation. Thus, theU.S. Government has certain rights in the invention.

FIELD OF THE INVENTION

The present invention relates generally to apparatus and method forspectrally encoded endoscopy and, more particularly to, e.g., apparatusfor obtaining information for a structure using spectrally-encodedendoscopy techniques and method for producing one or more opticalarrangements.

BACKGROUND OF THE INVENTION

Certain medical and technical applications utilize an ability to lookinside the patient's body or use a particular device when the availablepathways for probe advancement are of very narrow diameter (e.g., smallvessels, small ducts, small needles, cracks etc.).

Conventional miniature endoscopes are generally composed of fiber-opticimaging bundles. These conventional instruments have diameters thatrange of from approximately 250 μm to 1.0 mm. Since optical fibers havea finite diameter, a limited number of fibers can be incorporated intoone imaging bundle, resulting in a limited number of resolvableelements. The resultant image resolution and field of view provided bythese imaging devices may be insufficient for obtaining endoscopicimages of diagnostic quality in patients. The use of multiple fibers forimaging also increases the rigidity of the endoscopes, likely resultingin a bend radius of approximately 5 cm for the smallest probes in aclinical use. These technical limitations of fiber bundlemicroendoscopes, including a low number of resolvable points andincreased rigidity, have limited the widespread use of miniatureendoscopy in medicine.

U.S. Pat. No. 6,134,003 describes spectrally encoded endoscopy (“SEE”)techniques and arrangements which facilitate the use of a single opticalfiber to transmit one-dimensional (e.g., line) image by spectrallyencoding one spatial axis. By mechanically scanning this image line inthe direction perpendicular thereto, a two dimensional image of thescanned plane can be obtained outside of the probe. This conventionaltechnology provides a possibility for designing the probes that are ofslightly bigger diameter than an optical fiber. Probes in approximately100 μm diameter range may be developed using such SEE technology.

SEE techniques and systems facilitate a simultaneous detection of mostor all points along a one-dimensional line of the image. Encoding thespatial information on the sample can be accomplished by using a broadspectral bandwidth light source as the input to a single optical fiberendoscope.

FIG. 1 shows one such exemplary SEE system/probe 100. For example, at adistal end of the exemplary system/probe 100, light provided by thesource can be transmitted via an optical fiber 110, and collimated by acollimating lens 120. Further, the source spectrum of the light can bedispersed by a dispersing element 130 (e.g., a diffracting grating), andfocused by a lens 140 onto the sample. This optical configuration canprovide an illumination of the sample with an array of focused spots 150(e.g., on a wavelength-encoded axis), where each position (e.g., on thex-axis) can be encoded by a different wavelength (1). Following thetransmission back through the optical fiber, the reflectance as afunction of transverse location can be determined by measuring thereflected spectrum. High-speed spectral detection can occur externallyto the probe and, as a result, the detection of one line of image datamay not necessarily increase the diameter of the exemplary system/probe100. The other dimension (e.g., y, slow scan axis) of the image can beobtained by mechanically scanning the optical fiber and distal optics ata slower rate.

Accordingly, it may be beneficial to address and/or overcome at leastsome of the deficiencies described herein above.

OBJECTS AND SUMMARY OF THE INVENTION

One of the objectives of the present invention is to overcome certaindeficiencies and shortcomings of the prior art systems and methods(including those described herein above), and provide exemplaryembodiments of systems and methods for generating data using one or moreendoscopic microscopy techniques and, more particularly to e.g.,generating such data using one or more high-resolution endoscopicmicroscopy techniques.

For example, certain exemplary embodiments of the present invention canfacilitate the use and production of narrow diameter optical fiberprobes that use exemplary SEE techniques. Certain procedures andconfiguration to achieve the preferable optical and mechanicalfunctionality at the distal end of a narrow diameter fiber optical probefor SEE can be provided.

Different exemplary embodiments can be provided to incorporate theexemplary SEE optical functionality at a tip of the optical fiber inaccordance with certain concepts of the present invention. For example,different types of fibers can be used depending on the spectral regionand the size/flexibility preferences, e.g., single mode, multimode ordouble clad fibers can be used.

In one exemplary embodiment of the SEE system, the same channel can beused for illumination and collecting of the reflected light. Double cladfiber can be employed for improving the collecting efficiency andminimizing the speckle in the exemplary SEE system. For example, aregular telecommunication single mode fiber SMF28 can be used.

According to a particular exemplary embodiment of an apparatus forobtaining information for a structure according to the present inventioncan be provided. For example, the exemplary apparatus can include atleast one first optical fiber arrangement which is configured totransceive at least one first electro-magnetic radiation, and caninclude at least one fiber. The exemplary apparatus can also include atleast one second focusing arrangement in optical communication with theoptical fiber arrangement. The second arrangement can be configured tofocus and provide there through the first electro-magnetic radiation.Further, the exemplary apparatus can include at least one thirddispersive arrangement which is configured to receive a particularradiation which is the first electro-magnetic radiation and/or thefocused electro-magnetic radiation, and forward a dispersed radiationthereof to at least one section of the structure. At least one end ofthe fiber can be directly connected to the second focusing arrangementand/or the third dispersive arrangement.

According to still another exemplary embodiment of the presentinvention, the end and/or the section can be directly connected to thethird dispersive arrangement. The second focusing arrangement caninclude at least one optical element which may be directly connected theend. The second arrangement may include an optical component with anumerical aperture of at most 0.2, and the optical element may bedirectly connected the optical component. The second arrangement mayinclude an optical component with a numerical aperture of at most 0.2.The end may be directly connected to the optical component.

In yet another exemplary embodiment of the present invention, theparticular radiation can include a plurality of wavelengths and/or asingle wavelength that changes over time. The third dispersivearrangement may be configured to spatially separate the particularradiation into a plurality of signals having differing centerwavelengths. The first, second and third arrangement can be provided ina monolithic configuration. The third dispersive arrangement may be afiber grating, a blazed grating, a grism, a dual prism, a binary, prismand/or a holographic lens grating. The second focusing arrangement caninclude a gradient index lens, a reflective mirror lens gratingcombination and/or a diffractive lens.

According to a further exemplary embodiment of the present invention, atleast one fourth arrangement can be provided which is configured tocontrol a focal distance of the second focusing arrangement. The thirddispersive arrangement may include a balloon. The second focusingarrangement and the third dispersive arrangement can be provided in asingle arrangement. The single arrangement may be a holographicarrangement and/or a diffractive arrangement.

In addition, an exemplary embodiment of a method for producing anoptical arrangement can be provided. For example, a first set of opticalelements having a first size in a first configuration and a second setof optical elements in cooperation with the second set and having asecond size in a second configuration can be provided. The first andsecond sets can be clamped into a third set of optical elements. Thethird set can be polished, and a further set of optical elements may bedeposited on the polished set.

According to yet another exemplary embodiment of the present invention,the first set and/or the second set can be at least one set ofcylindrical optical elements. At least one of the cylindrical opticalelements may be an optical fiber. The third set may be polished at anangle with respect to the extension of at least one of the opticalelements. The angle can substantially correspond to a Littrow's angleand/or be substantially greater than 1 degree. The further set may be agrating, and/or can include a diffractive optical element. A layer canbe applied between elements of the first set and/or the second set. Thelayer may be composed of a thin material and/or a soft material.

Other features and advantages of the present invention will becomeapparent upon reading the following detailed description of embodimentsof the invention, when taken in conjunction with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects, features and advantages of the present invention willbecome apparent from the following detailed description taken inconjunction with the accompanying figures showing illustrativeembodiments of the present invention, in which:

FIG. 1 is a schematic diagram of a procedure for implementingone-dimensional space-to-spectrum encoding;

FIG. 2 is a schematic diagram of an exemplary embodiment of an SEEimaging system/probe;

FIG. 3 is a schematic diagram of another exemplary embodiment of the SEEimaging system/probe, in which a prism is used as a dispersing element;

FIG. 4 is a schematic diagram of an additional exemplary embodiment ofthe SEE imaging system/probe, in which a micro spherical lens is usedwith the grating following a lens;

FIG. 5 is a schematic diagram of a further exemplary embodiment of theSEE imaging system/probe, which has a micro spherical lens design withthe grating before the lens;

FIG. 6 is a schematic diagram of an exemplary embodiment of a microspherical lens configuration with the grating provided before the lens,and in which the lens can be formed by a drop of optical epoxy at a tipof a fiber;

FIG. 7 is a schematic diagram of an exemplary embodiment of anendoscopic system/probe that can use a holographic optical element(“HOE”) formed in a drop of photosensitized polymer combining thefunctionality of expansion, focusing and dispersing regions;

FIG. 8 is a schematic diagram of an exemplary embodiment of theendoscopic system/probe assembly that may be non-monolithic tofacilitate zooming and/or refocusing;

FIG. 9A is a schematic diagram of an exemplary embodiment of theendoscopic system/probe assembly having monolithic distal optics and agrism as a dispersing element in an exemplary configuration for sideimaging;

FIG. 9B is a schematic diagram of another exemplary embodiment of theendoscopic system/probe assembly having monolithic distal optics and adouble prism grism as a dispersing element in an exemplary configurationfor forward imaging;

FIG. 10A is a schematic diagram of an exemplary embodiment of acylindrical grating substrate with a tilted base for a Littrow regime;

FIG. 10B is a schematic diagram of an exemplary embodiment of aprismatic grating substrate with a tilted base for the Littrow regime;

FIG. 10C is a schematic diagram of another exemplary embodiment of thecylindrical grating substrate with a mirror tilted base and flatten sidefor the Littrow regime;

FIG. 10D is a schematic diagram another exemplary embodiment of theprismatic grating substrate with a mirror tilted base for the Littrowregime;

FIG. 11A is a schematic diagram of yet another exemplary embodiment ofthe endoscopic system/probe assembly in an exemplary balloon catheterconfiguration, in which approximately all of the optical functionalityis transferred to the balloon by via HOE that is deposited on theballoon surface;

FIG. 11B is a schematic diagram of still another exemplary embodiment ofthe endoscopic system/probe assembly in balloon catheter configuration,in which at least some optical functionality is transferred to theballoon by the use of high refractive index transparent liquid to fill athin wall balloon to form an inflatable focusing lens;

FIG. 12 is a schematic diagram of an exemplary embodiment of a cathetersystem/probe delivery technique using an exemplary guide catheter;

FIG. 13 is a schematic diagram of another exemplary embodiment of acatheter system/probe delivery procedure using an exemplary biopsyneedle;

FIG. 14 is a flow diagram of a method according to an exemplaryembodiment of the present invention for making the exemplary embodimentof the SEE system/probe shown in FIG. 2; and

FIG. 15 is an illustration of procedural steps of an exemplaryembodiment of a process for mounting grating substrates which can befacilitated for an exemplary grating fabrication process.

Throughout the figures, the same reference numerals and characters,unless otherwise stated, are used to denote like features, elements,components or portions of the illustrated embodiments. Moreover, whilethe subject invention will now be described in detail with reference tothe figures, it is done so in connection with the illustrativeembodiments. It is intended that changes and modifications can be madeto the described embodiments without departing from the true scope andspirit of the subject invention as defined by the appended claims.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Prior to providing a detailed description of the various exemplaryembodiments of the methods and systems for endoscopic microscopyaccording to the present invention, some introductory concepts andterminology are provided below. As used herein, the term “endoscopicprobe” can be used to describe one or more portions of an exemplaryembodiment of an endoscopic system, which can be inserted into a humanor animal body in order to obtain an image of tissue within the body.

Prior to describing the exemplary embodiments of the systems and/orprobes for spectrally encoded endoscopy according to the presentinvention, certain exemplary concepts and terminology are providedherein. For example, the term “endoscopic probe” may be used to describea portion of an endoscopic system, which can be inserted into a humanbody in order to obtain an image of tissue within the human body. Theterm “monolithic” may be used to describe a structure formed as a singlepiece, which can have more than one optical function. The term “hybrid”may be used to describe a structure formed as a plurality of pieces,e.g., each piece having one optical function.

The exemplary embodiments of the system, apparatus, probe and methoddescribed herein can apply to any wavelength of light orelectro-magnetic radiation, including but not limited to visible lightand near infrared light.

FIG. 2 shows an exemplary embodiment of a SEE imaging system/probe 200(e.g., endoscopic probe having a single mode fiber that deliver lightfrom a light source to the tip of the fiber) which can include anoptical fiber 210, an expansion region 220, a focusing region 230, anangled region 240 and a dispersing element 250 (e.g., grating). Theexemplary system/probe 200 can generate a spectrally encoded imagingsignal, e.g., a line 260 on the imaged surface with the longerwavelengths 280 deviated further from the probe axis than the shorterwavelengths 270.

The optical fiber 210 can be a single-mode fiber and/or a multi-modefiber (e.g., preferably single mode for preserving the phase relation ofthe source light and the light remitted by the sample). By facilitationa light delivery through the optical fiber 210, SEE capabilities can beprovided in a catheter or endoscope. Thus, a high-resolution microscopyof surfaces of the body accessible by endoscope can be facilitated bythe exemplary embodiment of the system/probe 200.

A multiple of (e.g., four) distinct regions with specific opticalproperties can be used to determine the system/probe functionality.

For example, the expansion region can be used to facilitate the beamthat is confined in the fiber core to expand and fill an aperture. Theexpansion region can be composed of optical glass (e.g., a piece ofcoreless fiber spliced to the main fiber and then cleaved to apredetermined length), optical epoxy, air, or transparent fluid. Indexmatching with the fiber core may be desirable for reducing the backreflection from the interface between the fiber and the expansionregion. Other techniques and/or arrangements for reducing the backreflection, e.g., anti-reflection coating or angle cleaving, can beemployed in case of air or other non-matching media used as an expansionregion.

In the focusing region, the diverging beam can be transformed to aconverging one. For example, a gradient index (“GRIN”) lens or sphericalmicro lens can be used as shall be described in more detail below withreference to other exemplary embodiments. For example, the GRIN lens canbe made by splicing a piece of GRIN fiber and cleaving it to apredetermined length. The spherical lens can be formed on the corelessfiber tip by melting it, by polishing, or by applying a small measuredamount of optical epoxy.

The angled region can be used to support the dispersing element and/orprovide an incidence tilt for the output direction and/or the desiredregime (Litrow) in certain cases (e.g., a diffraction grating). As withthe expansion region, different media can be used, and differenttechniques and/or arrangements for obtaining the desired tilt can beemployed. For example, some of such exemplary techniques can includeangle cleaving, polishing, molding of the optical epoxy etc.

The dispersing element can tilt different parts of the incident spectrumat different angles, thus producing the desired spatial spread of theincident light. It can be a prism made of high dispersion material or ahigh efficiency diffracting grating. It is possible to also produce agrating at the fiber tip. For example, transmitting or reflectinggratings can be used in different regimes depending on the application.

Other numerous combinations and permutations of the above-mentionedregions can provide a functional system/probe, certain exemplaryembodiments of which shall be described in further detail below. Forexample, two general types of dispersing elements can be used: prism ordiffracting grating. The holographic optical element that combines thedispersing power of the grating and the focusing power of a lens canalso be used as shown in FIG. 7.

Prism made of dispersing material can be used when the light source hasa very broad spectrum, e.g., a femto-second laser source withmicrostructured fiber for super-continuum generation. In such exemplarysource, the spectrum can span in visible and near infrared.

FIG. 3 shows another exemplary embodiment of the SEE system/probe 300which can include a single mode optical fiber 310 spliced to a corelessfiber 320 (e.g., the expansion region). Further, a short piece ofgradient refracting index (GRIN) fiber 330 can be spliced to thecoreless fiber (e.g., the focusing region). In addition, another shortpiece of coreless fiber 340 can be spliced to the focusing region 330.The output surface 350 may be angle polished/cleaved, thus forming arefracting boundary between the fiber 340 and the external medium 355(e.g., air, water or other liquid). In FIG. 3, an exemplary use of theprism 340 is illustrated as a dispersive element. With ananti-reflecting coating on the output surface 350, this exemplaryconfiguration can provide a high transmission efficiency. It may bedesirable for the angled region to be made of a highly dispersivematerial. In the case of a normal dispersion, longer wavelength parts ofthe original spectrum 370 may deviate less than the shorter wavelengths380, thus forming the imaging line 360.

Diffracting gratings can be preferable in the case of narrow band sourcebecause of the higher dispersing power that can be achieved with suchgratings. For example, the transmission and reflection diffractinggratings can be used. FIG. 5 shows a schematic diagram of a furtherexemplary embodiment of the SEE imaging system/probe 500, which has amicro spherical lens 530 with a grating 550 provided before the lens 530use of the reflection diffracting grating. In other exemplaryconfiguration, the use of reflection diffracting grating utilizes ahousing that can enlarge the system/probe. The additional details of theexemplary embodiment of the SEE system/probe 500 shall be described infurther detail below.

The selected dispersing element can be a transmission diffractinggrating. It is also possible to use other grating, e.g., a volumeholographic grating or a surface phase grating. The volume holographicgratings can exhibit a higher efficiency, but are less common, and someof the materials used therefore generally require sealing from thehumidity, as well as more expensive and difficult to replicate. Thesurface phase gratings may be less efficient, but are easy to replicateand mass-produce when a master grating is made. For both of theseexemplary elements, the grating can be a thin film (˜5-10 μm) that isapplied to the angled region.

FIG. 4 shows another exemplary embodiment of the SEE system/probe 400which can include a single mode optical fiber 410 spliced to a corelessfiber 420. In this exemplary embodiment, the tip of the expansion region420 can be melted to form a small spherical surface 425, and then a lowrefractive index epoxy 430 may be used to attach the grating 440 at anangle to the system/probe 400. In this exemplary system/probe 400, thefocusing region can be the surface that separates the expansion regionand the angled region. The longer wavelengths 460 of the originalspectrum may deviate more than the shorter wavelengths 470, thuspossibly forming the imaging line 450.

FIG. 5 shows the exemplary SEE probe 500 described above, which caninclude a single mode optical fiber 510 spliced to a coreless fiber 520.The tip of the expansion region 520 can be melted to form a ball 530.The ball may be polished at an angle (Littrow) and on the flat surface540 that can result from this exemplary procedure, a reflecting grating550 may be deposited. The light beam can expand in the expansion sectionafter exiting an end 510 of the core of the optical fiber 510, and maythen be dispersed by the grating 550. Different monochromatic beams thatcan result may then be focused by the near spherical surface of theglass ball to form the imaging line 560. The dispersing element may beprovided before the focusing element. The longer wavelengths 580 of theoriginal spectrum may deviate more than the shorter wavelengths 570.

FIG. 6 shows another exemplary embodiment of the SEE system/probe 600which may include a single mode optical fiber 610 spliced to a shortpiece of coreless fiber 620 that may be angle cleaved or polished at anangle (which can be the Littrow angle for the grating 630) and thegrating 630 may be deposited on the tip of the expansion region 620. Adrop of an optical epoxy 640 can be cured at the tip of the fiber 610 toprotect the transmission grating 630 and form the focusing surface 650.The dispersing element 630 can be provided before the focusing element650, and the expansion region 620 and the angled region 620 maycoincide. The longer wavelengths 670 of the original spectrum maydeviate more than the shorter wavelengths 680 to form the imaging line660.

FIG. 7 shows yet another exemplary embodiment of the SEE system/probe700, which can include a single mode optical fiber 710. A holographicoptical element (“HOE”) 730 written in a drop of photosensitive polymer720 can incorporate the optical functionality of the expansion, focusingand dispersing elements. The longer wavelengths 750 of the originalspectrum can deviate more than the shorter wavelengths 760 to form theimaging line 740.

FIG. 8 shows still another exemplary embodiment of the SEE system/probe800 which can include a static monolithic core 810 and a spinningflexible thin wall Teflon tubing 820 with the angled region 850 attachedto its end. An optical fiber 830, an expansion region 835, and afocusing region 840 may be attached/glued/spliced together to form thecore 810. A dispersing element/grating 857 can be deposited on thetilted output surface of the angled region 850. The glass-to-airinterfaces of the focusing region 840 845 and the angled region 850 853may be anti-reflection coated. Changing the gap between such elements byadvancing the core 810 can effectively change the distance 880 of theimaging line 860 to the output surface of the system/probe 800 (e.g.,the grating 875).

Exemplary non-monolithic configurations similar to those shown in theexemplary embodiment of FIG. 8 can allow for additional functionalitysuch as zooming and/or focusing to be provided in the distal probe end.Multi-lens configurations may also be implemented.

The use of a prism-grating combination (grism) may facilitate a controlof the angle of incidence and the probe output direction. Exemplaryarrangement which implements such configurations are shown in FIG. 9Aand FIG. 9B. In particular, FIG. 9A shows a further exemplary embodimentof the SEE imaging system/probe 900 which can include a static sheath905 with a transparent window 908 and a monolithic optical core 910 thatcan be scanned. The core can include an optical fiber 915, an expansionregion 917, a focusing element (e.g., a GRIN lens) 920, and a prism 925with the grating 930 deposited on its output surface. The opticalelements may be maintained together with a micro mechanical housing 940.This exemplary configuration may represent a side looking imagingsystem/probe.

FIG. 9B shows still another exemplary embodiment of the SEE imagingsystem/probe 950 which can include a static sheath 955 with atransparent window 958 and a monolithic optical core 960 that can bescanned. The core can include an optical fiber 965, an expansion region967, and a focusing element (GRIN lens) 970. A grating 980 may besandwiched between prisms 975 and 977. The optical elements may bemaintained together with a micro mechanical housing 990. This exemplaryconfiguration can represent a forward-looking imaging system/probe.

It may be beneficial for this exemplary application to utilize a gratingin Littrow regime when the angle of incidence is equal to the angle ofdiffraction (e.g., for the central wavelength). In this exemplaryconfiguration, the shape of the beam may not change after the grating,and thus provide an effective regime. FIGS. 10A-10C illustrate exemplaryembodiments of the substrate that can provide a Littrow regime for thegrating.

For example, FIG. 10A shows an exemplary embodiment of a diffractinggrating substrate 1000 which can include a cylindrical body 1005 withone side 1020 polished at the Littrow's angle 1015. FIG. 10B showsanother exemplary embodiment of the diffracting grating substrate 1025which includes a prismatic body 1030 with one side 1045 polished at theLittrow's angle 1040. FIG. 10C shows still another exemplary embodimentof the diffracting grating substrate 1050 which can include acylindrical body 1055 with one side 1057 polished at the complimentaryto Littrow's angle 1058 and a mirror 1087 deposited. Another flatsurface 1065 may be polished parallel to the cylinder axis where thegrating is to be deposited. FIG. 10D shows yet another exemplaryembodiment of the diffracting grating substrate 1075 which can include aprismatic body 1080 with one side 1087 polished at the complimentary toLittrow's angle 1085 and a mirror 1087 deposited. The grating isintended to be deposited on the side 1095. It should be understood thatthe illustrated sizes are merely exemplary, and other sizes are possibleand are within the scope of the present invention.

In certain exemplary applications, the system/probe can be small enoughto be introduced through a small opening, and big enough to be able toimage at big distances in a cavity. These conflicting preferences can bemet by using an inflating balloon with added optical functionality. Twosuch exemplary configurations are shown in FIGS. 11A and 11B.

In particular, FIG. 11A shows another exemplary embodiment of the SEEsystem/probe 1100 which can include a single mode optical fiber 1110. Aholographic optical element (“HOE”) 1125 written on the surface of theinflating balloon 1120 can incorporate the optical functionality of thefocusing and dispersing elements. The dispersed light may be focusedinto the imaging line 1130. When the exemplary system/probe 1100 isspun, the image of the area 1135 may be obtained. This exemplaryconfiguration may be further defined by the material availability forinfrared applications and the possible difficulties associated with theholographic process.

FIG. 11B shows still another exemplary embodiment of the SEEsystem/probe 1150 which can include a single mode optical fiber 1160. Aholographic optical element (“HOE”) 1165 written in a drop ofphotosensitive polymer 1067 deposited on the tip of the fiber 1060 canincorporate the optical functionality of the expansion, and dispersingelements. Further, the balloon catheter 1170 may be filled with a highrefractive index biocompatible liquid, thus forming a near sphericalrefracting focusing surface 1175. This exemplary configuration may befurther defined by the material availability for infrared applicationsand the possible difficulties associated with the holographic process.

One exemplary advantage of the various exemplary embodiments of thepresent invention may be the relative simple configurations and designsof the exemplary embodiments of the systems/probes. According to oneexemplary embodiment, e.g., the system/probe can include an opticalfiber with a modified tip. (See FIGS. 2-7). For example, thesystem/probe can illuminate a line at the object and acquire one line ofimage at a time. In order to acquire an image with this exemplarysystem/probe, it may be preferable that the imaging line is scanned intransverse direction across the object. This can be a repetitive or asingle scan. In such cases, an image or the surface that the line scanscan be acquired and displayed. The information obtained from theback-scattered light can be interpreted in various manners to representdifferent tissue types, different states of the same tissue, varioustypes of dysphasia, tissue damage etc. as well as motion of body liquidsand cells. Certain exemplary arrangements which can be used for placingthe probe and scanning the tissue may be as follows.

Catheter Exemplary Embodiments

Where catheters are used in medicine, a very thin wall sealed PTFE tubecan be used as a protective transparent sheath for the probe that can bedelivered through the lumen of a guide catheter to the area of interest(as shown in FIG. 12). When in place, the fiber inside the thin tube canbe scanned by rotating or by pulling in order to obtain an image. Ashort distal part of the catheter can be of a small diameter. Theproximal end can be of a bigger diameter with added additionalsprings/shafts to protect the fiber and convey the motion.

For example, FIG. 12 shows an exemplary embodiment of a catheter of theSEE system/probe 1200 which can include an optical core 1230. Theexemplary system/probe 1200 can be protected by a transparent sheath1220 that can allow the transmission of the imaging light 1240 into theregion of interest. The imaging catheter 1220 can be placed trough aguide catheter 1210.

Needle Exemplary Embodiments

For needle biopsies that are traditionally performed under CT, MRI, orultrasound guidance, the fiber optic probe may be inserted into thebiopsy needle (as shown in FIG. 13). In this exemplary configuration,the fiber optic probe may be embedded within the needle biopsy device orinserted through the lumen of the needle. The image can be acquiredduring the insertion of the needle or by rotating of the probe insidethe needle and, e.g., only looking at a limited angle

FIG. 13 shows another exemplary embodiment of a catheter of the SEEsystem/probe 1300 which can include an optical core 1330. The exemplarysystem/probe 1300 can be delivered to the region being imaged throughthe lumen of a biopsy needle 1320 that may be delivered through anendoscope or guide catheter 1310.

Intraoperative Exemplary Embodiments

For example, the exemplary system/probe may be incorporated into anelectrocautery device, scalpel, or be an independent hand-held device.

Exemplary Optical Parameters

One exemplary parameter for comparing different miniature endoscopetechnologies may be the number of resolvable points. This exemplaryparameter can be the limiting factor that may render a technology moreor less useful for the particular application. The total number ofresolvable points provided by the exemplary embodiments of the SEEsystem/probe (n) for the first diffraction order can be defined by:

$n = \left( \frac{{\Delta\lambda}\; d}{\lambda_{0}\Lambda \mspace{11mu} {\cos \left( \theta_{i} \right)}} \right)^{2}$

Exemplary determinations can indicate that for a source with a centerwavelength, λ₀, source bandwidth, Δλ, of 250 nm, a grating input angle,θ_(i), of 49° and a grating groove density, Λ, of 1800 lines per mm, a250 μm diameter SEE probe may facilitate imaging with, e.g., 40,000resolvable points. In comparison, a commercially available 300 μmdiameter fiber-optic image bundle (Holl Meditronics, 30-0084-00)contains only 1,600 resolvable points.

FIG. 14 shows a flow diagram of a method according to an exemplaryembodiment of the present invention for making the exemplary embodimentof the SEE system/probe shown in FIG. 2. In particular, the end ofSMF-28 optical fiber 210 or any other optical fiber can be stripped(step 1410). In step 1420, the spacer can be polished to a predeterminedlength. The GRIN lens can be polished to a predetermined length in step1430. Further, in step 1440, the grating 250 can be polished to apredetermined length and angle.

The results of step 1410 are provided to step 1450, in which the end ofthe optical fiber is cleaved. The results of steps 1420 and 1430 areprovided to step 1460, in which the spacer and GRIN lens are gluedtogether. The results of step 1440 are provided to step 1470, in whichthe grating 250 is deposited on the grating substrate. The results ofsteps 1450 and 1460 are provided to step 1475, in which the spacer-GRINlens assembly is glued to the optical fiber using an optical epoxy andthe spacing is varied to achieve the desired focal properties. Theresults of steps 1475 and 1470 are provided to step 1485 in which thegrating 250 bearing the grating substrate is glued to the GRIN lens. Instep 1480, flexible, optically clear, bio- and device-compatible sheathcan be provided for housing the imaging core. The results of steps 1480and 1485 are forwarded to step 1490, in which the exemplary system/probeis assembled, e.g., by inserting the core into the sheath and sealingand sterilizing the resultant assembly.

FIG. 15 shows an illustration of procedural steps of an exemplaryembodiment of a process for mounting grating substrates which can befacilitated for an exemplary grating fabrication process. It should beunderstood that dimensions and materials provided in FIG. 15 areexemplary, and numerous other dimensions and materials can be utilizedin accordance with the exemplary embodiments of the present invention.For example, several glass rods 1500, 1510 with different diameters canbe stacked and mounted together inside a particular mount 1520 into aparticular location 1525. The rods can be separated by a thin lead foil1530 (e.g., 127 μm thick). The rod stack can then be polished at anangle while inside the mount 1520. After polishing, the polished facecan be cleaned, and a grating 1540 may be fabricated, e.g., withoutdisassembling the pieces. When grating fabrication is completed, thepieces can be disassembled. The individual pieces may then be polishedfrom the other side 1550. The completed grating 1560 can then beassembled into the fiber or lens. The stack of fibers and the lead foil1530 is shown in FIG. 15 as a small square 1525 in the middle of theparticular mount 1520 (e.g., a holder). In a top projection indicated inFIG. 15, the same stack is shown as a parallelogram in the middle. Thisstack is further enlarged in the top right drawing of FIG. 15, labeled“Top view”. The final exemplary product (e.g., a completed piece 1560)can be obtained from one of the rods 1500 by shortening and/or polishingthe non-grating-carrying end to obtain the desired length.

The foregoing merely illustrates the principles of the invention.Various modifications and alterations to the described embodiments willbe apparent to those skilled in the art in view of the teachings herein.Indeed, the arrangements, systems and methods according to the exemplaryembodiments of the present invention can be used with and/or implementany OCT system, OFDI system, SD-OCT system or other imaging systems, andfor example with those described in International Patent ApplicationPCT/US2004/029148, filed Sep. 8, 2004, U.S. patent application Ser. No.11/266,779, filed Nov. 2, 2005, and U.S. patent application Ser. No.10/501,276, filed Jul. 9, 2004, the disclosures of which areincorporated by reference herein in their entireties. It will thus beappreciated that those skilled in the art will be able to devisenumerous systems, arrangements and methods which, although notexplicitly shown or described herein, embody the principles of theinvention and are thus within the spirit and scope of the presentinvention. In addition, to the extent that the prior art knowledge hasnot been explicitly incorporated by reference herein above, it isexplicitly being incorporated herein in its entirety. All publicationsreferenced herein above are incorporated herein by reference in theirentireties.

1-26. (canceled)
 27. A spectral encoding endoscopy apparatus, comprising: an lens optics configuration; a spacer configuration, wherein respective predetermined lengths of the spacer configuration and the lens optics configuration are changed by altering respective physical aspects thereof; and a dispersive optics configuration being modifiable to have a further predetermined length, wherein the changed spacer and changed lens optics configurations are attached to one another to form a combined spacer-lens optics configuration, wherein the modified dispersive optics configuration is attached to a substrate to form a grating substrate configuration; and the combined spacer-lens optics configuration is connected to an optical fiber, and the modified attached dispersed optics configuration is connected to the changed attached lens optics configuration to form the at least one spectral encoding endoscopy apparatus which extends along a particular axis, and wherein the dispersive optics configuration is modified to be at a predetermined angle with respect to the particular axis. 